Nanotech research holds promise for food industry, say scientists

The four major areas in food production that may benefit from nanotechnology development are microscale and nanoscale processing, product development, and methods and instrumentation design for improved safety and biosecurity, the scientists say in an article published in the current issue of the Journal of Food Science.

"The fact that systems with structural features on the nanoscale have physical, chemical, and biological properties substantially different from their macroscopic counterparts is changing the understanding of biological and physical phenomena in foodsystems,"​ they say.

Nanotechnology, which deals with controlling matter at near-atomic scales to produce unique or enhanced materials, products and devices, has been touted as the next revolution in many industries,including food manufacturing and packaging. Yet the public's concerns have been raised that nanostructured materials could potentially lead to unforeseen health or environmental hazards.

In the food area fears arise over the unknown consequences of digesting nano-scale particlesdesigned to behave in specific way in the body.

In the article scientists Jochen Weiss, Paul Takhistov, and Julian McClements give an overview ofthe current state of nanotechnology research in the food industry, providing processors with a headsup of the probable changes that may come their way in the sector.

"Strategies to apply nanoscience to the food industry are quite different from these more traditional applications ofnanotechnology,"​ the scientists noted. " Food processing is a multitechnological manufacturing industry involving a wide variety of raw materials, high biosafety requirements, and well-regulated technological processes."​

The potential benefits of nanotechnology have been recognized by many industries, and commercial products are already being manufactured, such as in the microelectronics, aerospace, and pharmaceutical industries. Developments in these industries are driven by fundamental and applied research in physics, chemistry, biology, engineering, and materials science.

In contrast, applications of nanotechnology within the food industry are rather limited, thescientists say.

Production of nanoscale structures for use in food science and technology therefore frequently relies on an in-depth understanding of thermodynamically driven self-assemblyprocesses, write the scientists.

They suggest areas of current research that could prove useful for the food sector in the near future includethe molecular design of protective surface systems, surface engineering, and various methods of manufacturing, such as electrospinning and nanofiltration.

Other areas where nanotechnology has the potential to impact food and agricultural systemsinclude security, disease-treatment delivery methods, tools for molecular and cellular biology, materials for pathogen detection, andthe protection of the environment.

Such examples include the use of nanotechnology for achieving further advancements in the security of manufacturing, processing, and shipping of food products through sensors for pathogen and contaminant detection.

Devices to maintain historical environmental records of a particular product and tracking of individualshipments could also be developed, they suggest.

Other nanotechnology developments are systems to provide the integration of sensing, localization, reporting, and remote control ofproducts, and transportation, and the encapsulation and delivery mechanisms for functional ingredients to their specific site ofaction.

The influence of the material properties of foods at the nanoscale level on their bioavailability and nutritional value has been highlightedby at least two studies. In addition, other scientists have investigated the relationship between the morphology of food materials and their bulk physicochemical properties.

Such studies include ones on biopolymers in solutions, gels, and films. One study foundfunctional nanostructures can incorporate individual biological molecules, which is useful in the development of biosensors that can use natural sugars or proteins as target-recognition groups.

"In summary, there are a large number of potential applications of nanotechnology within the food industry; however, many of these may be difficult to adopt commercially because they are either too expensive or too impractical to implement on an industrialscale,"​ the scientists concluded.

However a limited number of nanotechnology applications may have commercial potential in the near future. Most likely, the limited application of nanotechnology to the food industry will change as nanofabrication technologies become morecost-effective, they suggest.

Such areas include the development of functional ingredients such as drugs, vitamins,antimicrobials, antioxidants, flavorings, colourants, and preservatives.

Association colloids could be another fertile area for commercialisation. Association colloidsinclude surfactant micelles, vesicles, bilayers, reverse micelles, and liquid crystals - used formany years to encapsulate and deliver polar, nonpolar, or amphiphilic functional ingredients.

Nano-emulsions such as the use of high-pressure valve homogenizers or microfluidizers could beused to incorporate functional food components within the droplets, the interfacial region, or the continuous phase.

"While it is difficult to engineer the interfaces to be completely impermeable to compounds in the bulk phase that may interact with the encapsulated compounds, the rate of permeation can often be significantly reduced, thus increasing the kinetic stability of the bioactives,"the scientists stated.

Nanostructured multiple emulsions can be another area of work, used to create delivery systems with novel encapsulation and delivery properties. The most common examples of this are oil-in-water-in-oiland water-in-oil-in-water emulsions.

For example, a nanostructured emulsion would consist of nanometer-sized water droplets or reverse micellescontained within larger oil droplets that are dispersed within an aqueous continuous phase.

Functional food components could be encapsulated within the inner water phase, the oil phase, or the outer water phase, thereby making it possible to develop a single delivery system that contains multiple functional components.

The technology could be used to separate aqueous phase components that might adversely react with each other if they were present in the same aqueous phase.It could also be used to protect and release an aqueous phase component trapped within the inner water dropletsto a specific site such as the mouth, stomach, or small intestine, they suggest.

Another area for commercialisation is the use of nanostructured multilayer emulsions. Recent studiesshow that the use of multilayer emulsions can create novel delivery systems, they stated.

Such systems typically consist of oil droplets at the core surrounded by a shell of nanometer thick layers.The shell is comprised of different polyelectrolytes.

Under certain circumstances, emulsions containing oil droplets surrounded by multilayer interfaces have been found to have better stability against environmental stresses than conventional oil-in-water emulsions with single-layer interfaces,they stated.

The Journal of Food Science is a publication of the Institute of Food Technologists.